PT - JOURNAL ARTICLE AU - Biot, Claire AU - Rentsch, Cyrill A. AU - Gsponer, Joel R. AU - Birkhäuser, Frédéric D. AU - Jusforgues-Saklani, Hélène AU - Lemaître, Fabrice AU - Auriau, Charlotte AU - Bachmann, Alexander AU - Bousso, Philippe AU - Demangel, Caroline AU - Peduto, Lucie AU - Thalmann, George N. AU - Albert, Matthew L. TI - Preexisting BCG-Specific T Cells Improve Intravesical Immunotherapy for Bladder Cancer AID - 10.1126/scitranslmed.3003586 DP - 2012 Jun 06 TA - Science Translational Medicine PG - 137ra72--137ra72 VI - 4 IP - 137 4099 - http://stm.sciencemag.org/content/4/137/137ra72.short 4100 - http://stm.sciencemag.org/content/4/137/137ra72.full AB - Therapeutic intravesical instillation of bacillus Calmette-Guérin (BCG) is effective at triggering inflammation and eliciting successful tumor immunity in patients with non–muscle invasive bladder cancer, with 50 to 70% clinical response. Therapeutic success relies on repeated instillations of live BCG administered as adjuvant therapy shortly after tumor resection; however, the precise mechanisms remain unclear. Using an experimental model, we demonstrate that after a single instillation, BCG could disseminate to bladder draining lymph nodes and prime interferon-γ–producing T cells. Nonetheless, repeated instillations with live BCG were necessary for a robust T cell infiltration into the bladder. Parenteral exposure to BCG before instillation overcame this requirement; after the first intravesical instillation, BCG triggered a more robust acute inflammatory process and accelerated T cell entry into the bladder, as compared to the standard protocol. Moreover, parenteral exposure to BCG before intravesical treatment of an orthotopic tumor markedly improved response to therapy. Indeed, patients with sustained preexisting immunity to BCG showed a significant improvement in recurrence-free survival. Together, these data suggest that monitoring patients’ response to purified protein derivative, and, in their absence, boosting BCG responses by parenteral exposure before intravesical treatment initiation, may be a safe and effective means of improving intravesical BCG-induced clinical responses.